The overall objective is to elucidate the macromolecular basis of spermatozoan motility. We shall study the movement of sperm reactivated with ATP after their membranes have been removed with Triton X-100 and attempt to relate the parameters of the bending waves to the rate of ATP hydrolysis. The mechanism coordinating the active forces between the flagellar microtubules will be studied by observing the effects of experimental manipulations which produce modified bending waves. The interaction of the ATPase protein, dynein, with tubulin and other axonemal proteins will be studied using its functional recombination with salt-extracted tubules as an assay for physiological activity. Electron microscopy will be used in conjunction with selective extraction to localize the dynein isoenzymes within the axonemal structure. We shall use dark-field light microscopy to characterize the patterns of tubule sliding in trypsin-treated axonemes that have been depleted of one or more dynein isoenzymes. After developing the above techniques with sea urchin sperm, we intend to apply them to the study of sea urchin embryo cilia and mammalian sperm. The selective inhibition of sperm motility by vanadate will be studied in order to explore its possible usefulness as a vaginal contraceptive.